Current-regulating plug and socket



Sept. 7, 1948.

L. E. WEAN E TAL CURRENT-REGULATING rwe AND SOCKET 2 Sheets-Sheet 1 Filed Sept. 22. 1944 Inventor lazarzzz'aflwry Sept. 7, 1948. E. WEAN EI'AL.

CURRENT-REGULATING PLUG AND socxm 2 Sheets-Sheet 2 Filed Sept. 22, 1944 r r v n r jzzzaoizziil azz.

Patented Sept. 7.1948' CURRENT-REGULATING AND SOCKET PLUG Lincoln E. wean, Phlladclphia,.la., and Lawrence J. McCarty, Merchantv'ille, N. J.

Appucau se tembe 22, 1944, Serial No. 555,342

2 Claims. (CL 171-119) This invention relates to an electrical connector of the plug and socket type, and the primary object of the invention is to provide a connector of this kind having novel and efficient means interposed in the circuit between the plug and the socket oi. the connector for controlling the voltage of the current delivered to the socket, and thereby controll ng the voltage of current delivered to an appliance or translatingdevicewhose attachment plug is engaged in the socket of the connector.

A current-regulating plug and socket of the present kind may be used for many purposes. I

to a branch circuit in which there is a notice-- able voltage drop, and 'where the appliance or translating device will not function properly unless the drop in voltage is compensated for. The

' connector may also be employed for reducing the voltage of current delivered from the outlet receptacle to the appliance or translating device when the latter requires a lower voltage than that carried by the circuit to which the outlet receptacle is"connected.

An important object of the present invention is to provide a connector of the above kind wherein the voltage-regulating means embodies a transformer for changing the voltage of the current so that current of a different voltage is delivered to the output socket of the connector than that of the current receivedjrom the outlet receptacle by the'input plug of the connector. The transformer includes a secondary coil tapped at a plurality of points, fixed contacts connected with the respective taps, and a movable contact electrically connected to one terminal oi the output socket and manually operable to selectively engage a desired one of the fixed contacts so that the voltage of current delivered to the output socket may be varied at will, as desired.

A further object of the present invention is to provide a connector or the above kind in which the input plug has thermostatic means tor automatically opening the circuit from the central contact of said plug to the primaiy coil or the transformer, thereby discontinuing delivery of current to the output socket and the appliance or translating device when the circuit is overloaded.

A further object of the present invention is to provide a connector of the above kind which is comparatively simple and compact in construction, efilcient in operation, and otherwise well x 2 adapted to meet with the requirements for a successiul use.

This invention consists in the novel form. combination and arrangement of parts hereinafter more fully described. shown in the accompanyin drawings and claimed.

In the drawings, wherein like reference char acters indicate corresponding parts throughout the several views: i

Figure 1- is an elevational view of a currentregulating plug and socket constructed in accordance with the present invention.

Figure 2 is an enlarged substantially central longitudinal sectional view thereof.

Figure 3 is an enlarged fragmentary trans= verse section taken substantially on line 8-3 0! Figure l. I

Figure 4' is an enlarged fragmentary transverse section taken on line l- -d of Figure 1.

Figure 5 is an enlarged fragmentary longitudh nal section taken substantially on line -5 of Figure 2.

Figure 6 is an enlarged perspective view of the lever forming part of the re-setting' means for the thermostatic circuit-opening device forming part oi the connector shown in Figures 1 and 2.

- Figure l is an enlarged perspective view of the pull rod operated by the lever of Figure 6 and also forming part of said ire-setting means.

Figure 8 is a wiring diagram'showing the men ner of wiring the coils of thetransformer and tapping the secondary coil when the device is intended to increase the voltage of the current.

Figure 9 is a view similar to Figure a showing the manner of wiring the coils of the trans former and tapping the secondary coll thereof when the device is intended to decrease the volt age 0! the current.

Referring in. detail to the drawings, the pres= ent connector consists of a current-regulating plug and socket including a casing c having an input plug 5 at one end and an output socket T1 at the other end. The plug 6 is adapted to be threaded into a conventional outlet receptacle or lamp socket and includes an insulator 8 having a. threaded contact shell 9 mounted thereon and A provided at its outer end with an ordinary cenataacaa The casing is formed oi electrical insulating material, and mounted in spaced concentric relation to and within the casing 5 is a transformer including an iron core [4 and primary and secondary windings I5 and i5, respectively. Casing 5 is preferably apertured, as indicated at Ill, to facilitate dissipation of heat.

The central contact ill of plug 6 is connected to one side of winding l5 through the medium of a thermostatic circuit-opening device it and wire 19. Contact shell 9 is connected to the other side of winding I5 by means of a wire 20. When the voltage of the current is to be increased, the side of winding i5 which is connected to contact in is also connected at 2! to the central contact i3 of socket l, as shown in Figures 2 and 8. In this arrangement, corresponding sides of windings i5 and B6 are connected. as at 22.

A plurality of taps 23 are extended from the secondary winding "5 at a plurality of different points of the latter, each tap being connected to a difierent one of a plurality of fixed contacts 24. The contacts 24 are arranged in a series longitudinally of the casing 5 and are mounted upon one side. of the transformer in position to be selectively engaged by a movable contact 25 carried by a slide bar 26 mounted in a suitable guide 21 fixed to the inside of the casing 5. On one edge, the bar 26 has rack teeth 28 engaged by a pinion 29 carried by a shaft 30 journaled in and projecting outwardly through the casing 5. A handle or knob for operating shaft 30 is provided upon the outer end of the latter, as at M. The bar 26 is of conducting material, and through said bar and a wire 32, movable contact 25 is electrically connected with the contact shell 12 of socket 1. Thus, by engaging contact 25 with difierent ones of the contacts 2-4, the voltage of current delivered to the socket I may be varied. The adjustment of contact 25 to engage the desired one of the fixed contacts 24 is efi'ected by rotating pinion 29 to cause sliding movement of bar 26 in guide 21, such rotation of pinion 29 being efiected by turning knob 34 and shaft 30. Obviously, the greater the portion of coil l6 that is included in the circuit, the greater the voltage delivered to socket I, and vice versa.

When a reduction of the current voltage is desired, the side of coil l5 which is connected to contact I0 is connected to the corresponding side of coil 1'6, as at 22a in Figure 9. Also, in this arrangement, the side of coil 15 which is connected to contact 9 is also connected at 2Ia with contact l2 of socket l, the contact 25 being /connected at 32 to contact l3 of socket I. The

increase of voltage, while the other provides for a decrease of voltage of current delivered to socket I.

The thermostatic circuit-opening device I8 is arranged within the insulator 8 of plug 6 and includes a thermo-sensitive bimetallic bar 33 attached to the inner end of the central contact of plug 6. The inner end of bar 33 normally engages the free end of a pivoted contact 34 to held the latter in engagementwith a fixed contact 35 against the action' of a spring. Contact 35 is electrically connected by wire IS with coll l5. Pivoted to and extending inwardly fromthe contact 34, as well as extending freely through the contact 35, is a pull rod 3'! having a cross I moved outwardly by a spring 4-3.

pin 38 at its inner end and freely extending through a slot 39 of an angular lever 40 suitably pivotally mounted intermediate its ends within the plug 6. An arm 4! of lever 40 is pivoted to the inner end of a push rod 42 slidably extending through the plug 6 and normally The bar 33 is insulated from contact l0 and is surrounded by an electric resistance coil 44, one end of which is electrically connected to contact In and the other end of which is electrically connected to contact 34. The arrangement is such that when the circuit is overloaded, the increased amperage causes coil 44 to heat the thermostatic rod 33 so that the latter will flex in a direction to release contact 34. Spring 36 then swings contact 34 out of engagement with contact 35 so as to break the circuit.- When the bar 33 has. sufliciently cooled, the device may be re-set to again close the circuit by pushing inwardly on push rod 42 against the action of spring 43. When ,this is done, lever 40 is swung in a direction to engage cross pin 38 and thereby cause an inward pull on rod 31 so that contact 34 is swung into engagement with contact 35 against the action of spring 35, thereby allowing the thermostatic rod 33 to engage theend of contact 34 and maintain it engaged with contact 35 until the thermostatic rod 33 is again heated and caused to flex out of engagement with contact 34. It will thus be seen that the thermostatic device l8 offers the same protection as an ordinary fuse, in that it automatically opens the circuit when the latter is overloaded.

From the foregoing description, it is believed that the construction and operation, as well as the advantages, of the present invention will be readily understood -and appreciated by those skilled in the art. Minor changes may be made in the details of construction illustrated and described, such as fairly fall within the spirit and csope of the invention as claimed.

What we claim as new is:

1. A current-regulating plug and socket comprising a casing having an input plug at one end adapted for removable reception, in an outlet receptacle and an output socket at the other end adapted to removably receive an attachment plug, a transformer mounted in the casing and interposed in the circuit between said plug and said socket, said transformer comprising a primary winding connected'to the contacts of said input plug and a contact of said output socket and a secondary winding having a plurality of taps, a series of fixed contacts mounted within the casing at one side of said transformer and connected to the respective taps, a movable contact movable longitudinally of the casing and selectively engageable with any desired one of said fixed contacts, manually operable means including an operating member accessible exteriorly and at one side of the casing for moving said movable contact, and an electrical connection between said movable contact and the remaining contact of the output socket.

2. The construction defined in claim 1, in com bination with a grooved guide fixed to and arranged inside the casing, a longitudinal edge portion of said movable contact being slidably engaged in the groove of said guide, said manually operable means including a rack on the other longitudinal edge of said movable contact and a pinion meshing with said rack and having an operating shaft journaled in and pro- Jecflnz outwardly through the s ide of ma cu- LINCOLN E. WEAN. Number LAWRENCE J. MCCARTY. 954 51 I 1,458,091 BEEEBENCES CITED 2,036,982 The following references are of record in the 2,117,583

file of this patent: 

